DEVELOPMENTAL EXPRESSION PATTERN OF STRA6, A RETINOIC ACID-RESPONSIVEGENE ENCODING A NEW-TYPE OF MEMBRANE-PROTEIN

Retinoic acid plays important roles in development, growth and differe ntiation by regulating the expression of target genes. A new retinoic acid-inducible gene, Stra6, has been identified in P19 embryonal carci noma cells using a subtractive hybridization cDNA cloning technique. S tra6 codes for a very hydrophobic membrane protein of a new type, whic h does not display similarities with previously characterized integral membrane proteins. Stra6, which exhibits a specific pattern of expres sion during development and in the adult, is strongly expressed at the level of blood-organ barriers. Interestingly, in testis Sertoli cells , Stra6 has a spermatogenic cycle-dependent expression which is lost i n testes of RAR alpha null mutants where Stra6 is expressed in all tub ules. We suggest that the Stra6 protein may be a component of an as ye t unidentified transport machinery. (C) 1997 Elsevier Science Ireland Ltd.